1. Field of the Invention
The present invention relates to a so-called vertical pillow type packaging system with an improved flow of articles to be packaged.
2. Description of the Prior Art
A conventional packaging system will be described with reference to FIG. 1 showing one embodiment of the present invention.
In FIG. 1, after articles M discharged from a combination weighing apparatus 1 fall downward intermittently to a chute 203, they are packaged continuously by a bagging and packaging machine 200. While the articles M falling from above are filled into a tubular film F, the bagging and packaging machine 200 fuses (seals) and then cuts an upper end F1 of a film F positioned above the articles M by means of sealing jaws 202a provided on a tip end of an end sealer (sealing means) 202, to thereby continuously package products M1.
In the afore-mentioned packaging system, if the articles M are bulky such as potato chips, then they may interfere with one another at a passage-tapered portion A1 of a funnel-like hopper 203, the flow of the articles M become slower or they sometimes form a bridge and completely clog.
To solve such clogging, an auxiliary device 205 referred to as xe2x80x9cpokerxe2x80x9d is provided to force the articles M within a chute 203 to fall downward (see, for example, the Japanese Laid-Open Patent Publication No. 10-236408). Namely, the poker 205 is provided with a clapper H. The clapper H projects from an initial position indicated by a solid line into a position indicated by a double-dotted line, thereby forcing the articles M almost clogging within the chute 203 into the chute to cause them to fall downward.
In some cases, however, good operating timing at which the clapper H projects into the chute 203 is not taken and the clogging of the articles M cannot be completely removed. As a result, weight-defective products M1 are packaged and thus system productivity deteriorates. In addition, since the system operates at high speed, large amounts of articles M accumulate in a short period of time if the articles M begin clogging. It takes a lot of time and labor to remove the large amounts of accumulated articles M and restart the system, so that system operativity greatly decreases.
Meanwhile, if the articles M interfere with one another and the flow thereof becomes slower, the distance between a former group of articles M which are now falling and a later group of articles M becomes shorter and accordingly, the sealing means cannot operate at good timing. As a result, part of the later articles M are mixed into the former articles M or part of the former articles M are captured into the later articles M and packaged. As a result, weight-defective products M1 are produced and thus system productivity deteriorates.
It is, therefore, an object of the present invention to maintain the high productivity (production yield) and operativity of a packaging system by improving the operating timing of an auxiliary device and that of sealing means.
As mentioned above, the abnormal flow of articles is considered to be caused by the defective timing of an auxiliary device and that of seal means.
Taking this into consideration, a packaging system according to the one aspect of the present invention is intended to improve the defective timing of auxiliary device, and comprises an auxiliary device operating on the falling route at predetermined timing and facilitating or improving a flow of the articles; determination means for determining whether a state of the flow of the articles on the falling route is normal or abnormal; and change means for changing the predetermined timing of the auxiliary device according to the state of the flow of the articles determined by the determination means.
According to one aspect of the present invention, the predetermined operating timing of the auxiliary device is automatically changed, so that the state of flow is improved. It is thereby possible to suppress the occurrence of weight-defective products and to maintain the high productivity of the packaging system.
A packaging system according to another aspect of the present invention is intended to improve the defective timing of sealing means, and comprises sealing means operating on the falling route at predetermined timing, for sealing the end of the film in a direction vertical to a transfer direction of the film; determination means for determining whether a state of a flow of the articles on the falling route is normal or abnormal; and change means for changing the predetermined timing of the sealing means according to the state of the flow of the articles determined by the determination means.
According to another aspect of the present invention, the predetermined operating timing of the sealing means is automatically changed, so that the flow state of the articles is improved. It is thereby possible to suppress the occurrence of weight-defective products and to maintain the high productivity of the packaging system.
The term xe2x80x9carticlesxe2x80x9d referred to hereinabove and hereinafter is intended to mean a group of matters weighed and bagged, and the term xe2x80x9cproductxe2x80x9d referred to hereinabove and hereinafter is intended to mean the bagged group.
The term xe2x80x9cfalling routexe2x80x9d referred to hereinabove and hereinafter is intended to mean the route of the articles in the packaging machine or upstream of packaging machine, which route is taken by the articles discharged from a weighing apparatus or the like until they are filled into a bag by a packaging machine.
The term xe2x80x9ca state of the flow of articlesxe2x80x9d referred to hereinabove and hereinafter is intended to mean a state of the articles on the falling route and to encompass the clogging of the articles on the falling route.
As xe2x80x9cdetermination meansxe2x80x9d, may be used means for determining whether the state of the flow of the articles is normal or abnormal based on the weight of a product packaged, or on the weight difference between before packaging and after packaging.
xe2x80x9cChange meansxe2x80x9d preferably feedback-controls the operating timing of an auxiliary device and/or that of the sealing means while using a signal from the determination means as an input.
The term xe2x80x9cfeedback controlxe2x80x9d means detecting a control result, determining whether or not the result is appropriate, transmitting an appropriate correction signal and controlling a target as originally commanded. This control can be carried out based on, for example, surplus or shortage of the weight of a packaged product, the frequency of surplus or shortage thereof and/or the surplus or shortage amount thereof.
Further, according to the present invention, if there is provided a timing storage for updating and storing the operating timing of the auxiliary device or that of the sealing means according to the type of the articles or products, it is possible to minutely change the operating timing according to the type of the articles or products and to thereby maintain the high productivity of the packaging system.